Occurrence and pathogenicity of Botryosphaeria dothidea as the causal agent of shoot blight on japanese pear in the State of Santa Catarina, Brazil.

In Santa Catarina, at Frei Rogerio, Otacilio Costa, Campo Belo do Sul and Cacador counties, where the majority of the Japanese pear orchards are, the occurrence ofa new disease was verified, mainly in orchards of cultivar Kousui. The disease is characterized by the drought of branches with progressive death of the plant. Isolations were made from infected branches, and a fungus identified as Fusicoccum aesculi was obtained. By artificial inoculation, pseudothecia corresponding to the teleomorph Botryosphaeria dothidea were produced with bitunicate asci and ascospores measuring 20.2 x 8.7 μm, one-celled, hyaline, and ovoid. Pycnidia with hyaline, one-celled, ellipsoid to fusoid conidia, measuring 20.6 x 7.5 μm corresponding to the anamorph Fusicoccum aesculi were produced. Single-celled, hyaline microconidia were also present. The canker development was bigger on Japanese pears cv. Kousui than on cv. Housui. This is the first verification of the occurrence of the shoot blight on Japanese pear caused by Botryosphaeria dothidea in Santa Catarina State, Brazil.